Reseach on Wave Phenomena in Hydraulic Lines : 5th Report, Coupled Vibration in Bending and Branching Lines

Abstract

The roles of the lateral oscillation of a pipe in the coupled vibrations of pipes with oil in hydraulic circuits are receiving attention. The vibrations are theoretically analyzed under the assumption that the pulsation of oil and the longitudinal and lateral oscillations of a pipe are coupled at pipe ends alone and have no interactions elsewhere. Solid viscosity is introduced into the dynamics of a pipe wall as previously to explain the damping of pipe oscillations. The pipe oscillation in the lateral direction is mathematically represented by several equations of bending vibration of a beam. The vibration experiments are run in the unrestrained L-shaped and T-shaped lines with fixed terminals, and characteristic resonant phenomena of bending and branching lines are observed. The experimental results reveal the significant roles of the lateral pipe motion and the feasibility of the analytical procedure developed here.